/Engine/Source/Runtime/AIModule/Classes/BehaviorTree/BehaviorTreeComponent.h
Add unique Id of newly created subtree to KnownInstances list and return its index
uint8 UpdateInstanceId ( [UBehaviorTree](API\Runtime\AIModule\BehaviorTree\UBehaviorTree) * TreeAsset, const [UBTNode](API\Runtime\AIModule\BehaviorTree\UBTNode) * OriginNode, int32 OriginInstanceIdx )